US4366361A - Method of producing an electrical component - Google Patents

Method of producing an electrical component Download PDF

Info

Publication number
US4366361A
US4366361A US06/308,817 US30881781A US4366361A US 4366361 A US4366361 A US 4366361A US 30881781 A US30881781 A US 30881781A US 4366361 A US4366361 A US 4366361A
Authority
US
United States
Prior art keywords
compact
powder
support member
amperes
passing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US06/308,817
Other languages
English (en)
Inventor
Brian R. Allen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ZF International UK Ltd
Original Assignee
Lucas Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lucas Industries Ltd filed Critical Lucas Industries Ltd
Assigned to LUCAS INDUSTRIES LIMITED, A BRITISH COMPANY reassignment LUCAS INDUSTRIES LIMITED, A BRITISH COMPANY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: ALLEN, BRIAN R.
Application granted granted Critical
Publication of US4366361A publication Critical patent/US4366361A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/14—Both compacting and sintering simultaneously
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/06—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
    • B22F7/08—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools with one or more parts not made from powder
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K11/00—Resistance welding; Severing by resistance heating
    • B23K11/16—Resistance welding; Severing by resistance heating taking account of the properties of the material to be welded
    • B23K11/20—Resistance welding; Severing by resistance heating taking account of the properties of the material to be welded of different metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R43/00—Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors
    • H01R43/12—Manufacture of brushes

Definitions

  • This invention relates to a method of producing an electrical component and in particular, a brush for a dynamo electric machine.
  • Brushes for dynamo electric machines are well known in the prior art. Such brushes customarily include a conductive brush body, a conductive support structure carried by the brush body, and a conductive lead connected to the brush body or support structure.
  • the brush bodies of the prior art have been customarily formed from a compacted powder mixture.
  • the invention resides in a method of producing a brush for a dynamo electric machine, comprising the step of passing a heating current through a powder compact of the brush material and a conductive member in electrical contact with said powder compact so as to sinter the compact and connect the conductive member to the compact.
  • the passage of current is performed in two stages, the current passed during the first stage being less than that during the second stage.
  • the current passed during the first stage is between 1500 amperes and 1800 amperes and is between 2200 amperes and 2400 amperes during the second stage.
  • the powder compact includes copper, lead, carbon and a hard phase.
  • the hard phase is silicon carbide or ferromanganese.
  • the powder compact also contains tin.
  • the heating current is passed between a pair of electrodes which urge the conductive member and the powder compact into engagement with each other.
  • the brush material powder is compacted prior to its introduction between the electrodes.
  • compaction of the brush material powder is effected by using the electrodes to compress the powder.
  • the conductive member is in the form of a support member for the brush and conveniently is formed of steel, aluminium, brass, phosphor bronze or copper.
  • the support member is coated with a bonding material different from the support member material and in the form of copper, nickel or bronze.
  • said support member is adapted to have an electrical lead connected thereto and the method includes the further step of connecting the lead to the support member.
  • the connecting step is effected by resistance welding.
  • the step of passing the heating current through the powder compact and the conductive support member also serves to physically and electrically connect a conductive lead to the support member and the compact.
  • the compact and/or support member is shaped to define an opening in which the lead is received.
  • a heat sink is mounted in thermal connection with the conductive lead during passage of the heating current.
  • the conductive member is defined by an electrical lead.
  • FIG. 1 is an exploded, perspective view of a brush produced by a method according to a first example of the invention
  • FIG. 2 is a perspective view showing one stage during a method according to a second example of the present invention.
  • FIG. 3 is a perspective view of a brush produced by a method according to a modification of the second example.
  • FIG. 4 is a sectional view of a brush produced by a method according to a further modification of the second example.
  • the brush shown is intended for use in a dynamo electric machine having a face-type commutator and includes a generally wedge-shaped body 11 which, in use, engages the commutator at one end surface 12 of the body.
  • a substantially U-shaped, conductive support member 15 Secured to the opposite end surface 13 of the body 11 is a substantially U-shaped, conductive support member 15 which in use serves to support the brush in the brush holder of the dynamo electric machine.
  • the surface 13 is secured to the base 14 of the member 15 so that the limbs 16,17 of the member project away from the body.
  • the base 14 is tapered so as to be substantially complementary with the end surface 13, and is joined to the limbs 16,17 at its mutually inclined opposite sides respectively.
  • the support member 15 is formed from 0.03 inch thick mild steel sheet which is bent to the required shape and plated with nickel to a thickness of 0.001 inch.
  • the nickel coating assists in bonding the brush body 11 to the backing member 15 although, as an alternative to nickel, other bonding materials such as copper and bronze can be used. Nickel is, however, preferred.
  • the support member can be formed of aluminium brass, phosphor bronze or copper, instead of mild steel.
  • the brush includes a flexible, conductive lead 18 which is secured to the limb 17 of the support member 15 and which is preferably formed of tough pitch, high conductivity copper.
  • the body 11 is formed by sintering a compacted powder mixture having the following composition by weight:
  • Silicon carbide--1.7% (less than 25 micron average particle size).
  • the mixture also contains 0.1 parts by weight of a zinc stearate lubricant for every 100 parts by weight of the composition defined above.
  • the lubricant is present to assist compaction of the powder and reduce wear of the dies used to effect compaction, but the amount of lubricant is reduced to a minimum so as to avoid defects in the product as a result of excess volatilisation during sintering.
  • the copper powder employed in the above mixture had a purity of at least 99%, the major impurities being lead (maximum of 0.2% by weight) and oxygen (maximum 0.2% by weight). Moreover, a particle size analysis of the copper powder showed that not more than 0.2% by weight had a size in excess of 53 microns.
  • the lead powder employed in the mixture had a purity of at least 99.95% so that the effect of any impurities was negligible, and a particle size analysis showed that 1% by weight of the lead powder had a particle size in excess of 150 microns, 10% by weight had a particle size between 75 and 150 microns and 15% by weight had a particle size between 45 and 75 microns, the particle size of the remainder being 45 microns or below.
  • the tin powder had a purity of at least 99% again making the effect of impurities negligible and particle size analysis showed that about 97.5% by weight of the tin powder had a particle size below 53 microns.
  • the graphite powder 99.5% by weight had a particle size below 45 microns and the purity of the powder was between 96 and 97%, the major impurities after ashing being 1.4% silica, 0.93% by weight alumina, 0.2% by weight calcia, 0.07% by weight each of sulphur and magnesia, 0.68% by weight iron and not more than 0.2% by weight moisture.
  • the silicon carbide powder had a mean particle size of 13 microns and was 98.7% pure, the impurities present being 0.48% by weight silica, 0.3% by weight silicon, 0.9% by weight iron, 0.1% by weight aluminium and 0.3% by weight carbon.
  • the powder mixture described above is initially introduced into a die cavity of the shape of the required body 11, whereafter the mixture is compressed at an applied load of between 10 and 35 tons per square inch (hereinafter T/in 2 ), preferably 30 T/in 2 , to a thickness between the surfaces 12, 13 of 0.30 to 0.32 inch.
  • T/in 2 tons per square inch
  • the compressed mixture is then located on the support member 15, which at this stage is preferably in the form of a planar sheet of the backing material, the sheet being bent to the required shape after the subsequent resistance sintering operation.
  • the resultant assembly is then inserted between the tips of a pair of sintering electrodes, the tips conveniently being formed of steel, molybdenum, tungsten, elkonite or carbon.
  • the electrodes are then urged against the support member 15 and the powder compact with an applied load of 20 pounds force (hereinafter lb. F) and simultaneously a current of between 1500 amperes and 1800 amperes, preferably 1650 amperes, is passed between the electrodes.
  • the current is maintained at this value for 1.5 to 2 seconds to precondition the powder mixture which is found to improve the consistency of the properties of the final brush.
  • the current is then increased to between 2200 amperes and 2400 amperes, preferably 2300 amperes, for a further 5-6 seconds, during which time the powder mixture is resistance sintered to produce the body 11 and the support member 15 is resistance brazed to the body 11.
  • the entire resistance heating operation is performed in ambient atmosphere.
  • the sintered body 11 is found to be strongly bonded to the member 15, and to have the required physical and electrical properties for an electrical brush despite the varying particle sizes in the powder mixture and the temperature gradients which necessarily build up between the member 15 and the surface 12 during sintering.
  • the relatively high thermal conductivity of the electrode tip in contact with the member 15 causes it to act as a heat sink so that the temperature gradients generated can be as high as 250° C.
  • the surface 12 is found to consist of copper/tin grains surrounded by a grain boundary layer of lead, where the lead has melted and flowed at the high temperatures produced in this region, while adjacent the surface 12 heterogeneous lead-rich areas are present in the microstructure.
  • the member 15 is, if necessary, bent to the required shape by passing the assembly through a sizing die which also ensures that the body 11 is of the required dimensions.
  • the brush is then completed by resistance welding the lead 18 to the base 14 of the support member. This process is effected by passing a welding current between a tungsten electrode engaging the lead 18 and a copper electrode formed with a recess which is complementary with the body 11 and in which the body is engaged.
  • the welding parameters employed are an alternating current of 1800 amperes passed for 4 cycles of a 50 cycle supply and a force of 75 lb.f applied to the electrodes to urge the lead 18 and limb 17 into interengagement.
  • the brush according to the above example is intended for use with a face-type commutator of the kind in which the insulating material between adjacent conductive segments extends flush with the brush engaging surfaces of the segments. It is therefore necessary that the brush is able to cope with the variation in material at the brush engaging surface of the commutator while at the same time exhibiting a low wear rate of the brush together with a low rate of commutator wear.
  • the brush of the above example is tested with such a commutator, it is found that the brush operates satisfactorily and both the commutator and the brush exhibit a low rate of wear.
  • the step of separately compacting the powder mixture for the body 11 is omitted.
  • the uncompacted powder mixture is poured on top of the support member with the latter being received in a die cavity defined in a die formed of carbon or a ceramic material such as silicon nitride or alumina.
  • the powder mixture is then compacted between the pair of sintering electrodes employed in the previous example, while at the same time a heating current is passed in two stages between the electrodes to sinter the powder mixture into the body 11 and braze the support member 15 to the body 11.
  • Completion of the brush then proceeds in the manner described above.
  • the support member is conveniently formed of aluminium or copper without the provision of a coating of a bonding material.
  • the brush in the second example it is required to produce a brush for use with a face-type commutator, the brush including a generally wedge-shaped body having a conductive lead 21 and a substantially U-shaped, conductive support member 22 secured to one end surface of the body.
  • the body is formed from the powder mixture employed in the previous example and to produce the body, the required amounts of the constituents of the mixture are initially introduced into a Turbula mixer and mixed for 80 minutes. The resultant powder is then poured into the die cavity defined within a press, whereafter the mixture is compressed at an applied load of between 10 and 35 T/in 2 preferably 30 T/in 2 , into a compact 23 of the required shape for the brush body.
  • the compact 23 is formed with a semi-cylindrical recess 24 in the end surface 25 of the compact to which the lead 21 and support member 22 are to be secured.
  • the recess 24 was 0.312 inch long and the cylinder defined in part of the recess was circular and had a diameter of 0.105 inch.
  • the recess 24 is conveniently formed by a drilling operation, or more preferably by suitable shaping of the punches used to produce the compact 23.
  • the conductive lead 21 is defined by a length of copper braid, which in said one practical embodiment had seven entwined strands, each of which consisted of 36 copper wires 0.0048 inch in diameter.
  • the braid is cut to length electrically so as to bond the cut ends of the wires in the braid, whereafter the cut end of the braid is inserted in the recess 24.
  • the electrodes are conveniently formed of steel, molybdenum, tungsten, elkonite or carbon and preferably a water-cooled copper heat sink is mounted in thermal connection with the lead 21 over a short length of the lead, conveniently 0.5 inch, positioned as close as possible to the compact 23 and support member 22.
  • the sintering electrodes are then urged against the support member 22 and the compact 21 with an applied load of 20 lb.f and a two-stage electrical heating process is performed on the assembly in the manner described in the previous example.
  • the powder compact is resistance sintered to produce the brush body and the lead 21 is resistance brazed to the body and the support member 22.
  • the arrangement is such that the sintering electrodes urge the support member into physical contact with the surface 25 of the compact 23, whereby the passage of current also serves to resistance braze the support member to the brush body.
  • the brush of this modification is produced by the technique of the second example, but the support member 22 is now in the form of a planar sheet of copper plated steel which has been stamped to define a recess 26 in the surface of the sheet to be presented to the commutator body.
  • the electrical lead 21 of the brush is therefore received in the recess 26 so as to be trapped between the support member 22 and the brush body.
  • the technique of the second example is also employed in this further modification, but now the conductive lead 21 is located in an elongated slot 27 formed in a generally planar support member 22.
  • the support member is omitted and the resistance heating operation serves merely to sinter the powder compact 23 and resistance braze the lead 21 to the sintered compact.
  • the body 11 of the brush has been composed of a sintered mixture of copper, lead, tin, carbon and silicon carbide as an electrically conductive ceramic hard phase.
  • the indentation hardness (VPN) value of silicon carbide powder is between 1890 and 3430 (mean 2876) using a 200 g load which would normally be considered as more suitable for cutting tools and abrasives.
  • the method described above can, however, also be employed with brush compositions using a metallic hard phase, especially ferromanganese which has a VPN value of only between 782 and 1033 using a 100 g load.
  • the brush shown in FIG. 1 is produced from a starting mixture having the following composition by weight:
  • the mixture also contains 0.1 parts by weight of a zinc stearate lubricant for every 100 parts by weight of the composition defined above.
  • a zinc stearate lubricant for every 100 parts by weight of the composition defined above.
  • copper, lead, tin and graphite powders in mixture were the same as those employed in the previous example whereas the ferromanganese had a particle size of less than 75 microns.
  • the mixture is compacted as described above to a density of 6.87 g/cc and is then resistance sintered and brazed to a backing member using the same parameters as in the first example.
  • resistance sintering it is found that there is little tendency for the ferromanganese to lose its hardness as a result of the manganese diffusing away from the ferromanganese particles, whereas this is found to be a problem if conventional furnace sintering is employed.
  • After resistance welding of the necessary electrical lead to the backing member it is found that the resultant brush performs satisfactorily when employed in a road vehicle starter motor employing a face-type commutator of the kind referred to above.
  • the brush was found to exhibit a maximum wear rate of about 6.4 ⁇ 10 -3 inch/1000 operations, while the commutator wear was about 4 ⁇ 10 -3 inch after 30000 operations.
  • the method of the third example was also repeated with ferromanganese powder having a maximum particle size of 390 microns and in this case the resultant brush had a maximum wear rate of 6.2 ⁇ 10 -3 inch/1000 operations, whereas the commutator wear after 34,447 operations was 8 ⁇ 10 -3 inch.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Composite Materials (AREA)
  • Materials Engineering (AREA)
  • Motor Or Generator Current Collectors (AREA)
  • Manufacturing Of Electrical Connectors (AREA)
US06/308,817 1976-04-09 1981-10-05 Method of producing an electrical component Expired - Fee Related US4366361A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB14473/76A GB1571101A (en) 1976-04-09 1976-04-09 Method of producing a sintered electrical component
GB14473/76 1976-04-09

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US06082157 Continuation 1979-10-05

Publications (1)

Publication Number Publication Date
US4366361A true US4366361A (en) 1982-12-28

Family

ID=10041831

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/308,817 Expired - Fee Related US4366361A (en) 1976-04-09 1981-10-05 Method of producing an electrical component

Country Status (13)

Country Link
US (1) US4366361A (de)
JP (1) JPS52124107A (de)
AR (1) AR213520A1 (de)
AU (1) AU501504B2 (de)
BR (1) BR7702195A (de)
DE (1) DE2715347A1 (de)
ES (1) ES457674A1 (de)
FR (1) FR2347800A1 (de)
GB (1) GB1571101A (de)
IN (1) IN147816B (de)
IT (1) IT1079496B (de)
NL (1) NL7703749A (de)
ZA (1) ZA771852B (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4788627A (en) * 1986-06-06 1988-11-29 Tektronix, Inc. Heat sink device using composite metal alloy
EP1003269A1 (de) * 1997-08-06 2000-05-24 Mitsuba Corporation Kohlekommutator und verfahren zu dessen herstellung
EP1162022A1 (de) * 2000-06-07 2001-12-12 Sumitomo Coal Mining Co., Ltd. Elektrisches Verbindungsverfahren, Vorrichtung und verbundene Einheit von Elementen
EP1270753A1 (de) * 2000-03-27 2003-01-02 Komatsu Ltd. Gesinterter Werkstoff und Kontaktbauteil aus gesintertem Verbundwerkstoff
US6679933B1 (en) * 1998-12-16 2004-01-20 Victorian Rail Track Low resistivity materials with improved wear performance for electrical current transfer and methods for preparing same
US6822375B2 (en) * 2000-02-23 2004-11-23 Murata Manufacturing Co., Ltd. Vibrating gyroscope and electronic device using the same having a driving circuit, a detection circuit and four supporting members with different rigidities, different shapes, different cross sections, different materials and different lengths

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2853721A1 (de) * 1978-12-13 1980-07-17 Wenzel Rekofa Gmbh Kohlebuerste mit isolierhalterung sowie verfahren zu ihrer herstellung
EP0333600B1 (de) * 1988-02-25 1993-05-12 Merlin Gerin Verfahren zur Herstellung eines Verbundkörpers,z.b.für elektrische Kontakte
FR2633855B1 (fr) * 1988-07-06 1994-05-06 Merlin Et Gerin Procede de fabrication d'une piece composite et contact electrique a pastille de contact fabrique selon ce procede
US5443615A (en) * 1991-02-08 1995-08-22 Honda Giken Kogyo Kabushiki Kaisha Molded ceramic articles
GB2243160B (en) * 1990-02-13 1994-08-10 Honda Motor Co Ltd A method of producing a moulded article
FR2709611B1 (fr) * 1993-09-02 1995-11-10 Lorraine Carbone Procédé de fabrication de balais multicouches et balais obtenus par le procédé.

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2454579A (en) * 1946-08-17 1948-11-23 Gen Electric Carbon brush element
US2509021A (en) * 1946-09-12 1950-05-23 Gen Electric Electrical contact member and method of making the same
US3067319A (en) * 1959-11-10 1962-12-04 Air Reduction Metal-graphite brush with welded shunt
US3069261A (en) * 1957-10-25 1962-12-18 Globe Union Inc Method of making porous metal bodies
US3601645A (en) * 1968-05-23 1971-08-24 Morganite Carbon Ltd Electrical contact brushes
US3946192A (en) * 1973-05-19 1976-03-23 Girling Limited Method of manufacturing a friction disc

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2454579A (en) * 1946-08-17 1948-11-23 Gen Electric Carbon brush element
US2509021A (en) * 1946-09-12 1950-05-23 Gen Electric Electrical contact member and method of making the same
US3069261A (en) * 1957-10-25 1962-12-18 Globe Union Inc Method of making porous metal bodies
US3067319A (en) * 1959-11-10 1962-12-04 Air Reduction Metal-graphite brush with welded shunt
US3601645A (en) * 1968-05-23 1971-08-24 Morganite Carbon Ltd Electrical contact brushes
US3946192A (en) * 1973-05-19 1976-03-23 Girling Limited Method of manufacturing a friction disc

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Goetzel et al., Electrically Activated Pressure-Sintering (Spark Sintering) of Titanium Aluminum Vandium Alloy Powders, Modern Devs. of Powder Metallurgy, V. #4, Hauser ed., Plenum Press, 1971. *
Shaw, J. M., Resistance Sintering of Iron and Steel Powders, Welding and Metal Fabrication, Dec. 1963, pp. 505 to 508. *

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4788627A (en) * 1986-06-06 1988-11-29 Tektronix, Inc. Heat sink device using composite metal alloy
US6222298B1 (en) 1997-06-08 2001-04-24 Mitsuba Corporation Carbon commutator and method for producing the same
EP1003269A1 (de) * 1997-08-06 2000-05-24 Mitsuba Corporation Kohlekommutator und verfahren zu dessen herstellung
EP1003269A4 (de) * 1997-08-06 2002-03-20 Mitsuba Corp Kohlekommutator und verfahren zu dessen herstellung
US6679933B1 (en) * 1998-12-16 2004-01-20 Victorian Rail Track Low resistivity materials with improved wear performance for electrical current transfer and methods for preparing same
US6822375B2 (en) * 2000-02-23 2004-11-23 Murata Manufacturing Co., Ltd. Vibrating gyroscope and electronic device using the same having a driving circuit, a detection circuit and four supporting members with different rigidities, different shapes, different cross sections, different materials and different lengths
EP1270753A1 (de) * 2000-03-27 2003-01-02 Komatsu Ltd. Gesinterter Werkstoff und Kontaktbauteil aus gesintertem Verbundwerkstoff
EP1162022A1 (de) * 2000-06-07 2001-12-12 Sumitomo Coal Mining Co., Ltd. Elektrisches Verbindungsverfahren, Vorrichtung und verbundene Einheit von Elementen
US6515250B2 (en) 2000-06-07 2003-02-04 Sumitomo Coal Mining Co., Ltd. Electric joining method and apparatus and a joined unit of members
US20030106877A1 (en) * 2000-06-07 2003-06-12 Sumitomo Coal Mining Co., Ltd. Electric joining method and apparatus and a joined unit of members
US6899265B2 (en) 2000-06-07 2005-05-31 Sumitomo Coal Mining Co., Ltd. Electric joining method and apparatus and a joined unit of members

Also Published As

Publication number Publication date
ES457674A1 (es) 1978-02-01
AR213520A1 (es) 1979-02-15
FR2347800A1 (fr) 1977-11-04
AU501504B2 (en) 1979-06-21
IN147816B (de) 1980-07-05
ZA771852B (en) 1978-02-22
GB1571101A (en) 1980-07-09
NL7703749A (nl) 1977-10-11
IT1079496B (it) 1985-05-13
DE2715347A1 (de) 1977-10-20
FR2347800B1 (de) 1982-02-05
AU2379577A (en) 1978-10-05
BR7702195A (pt) 1978-02-21
JPS52124107A (en) 1977-10-18

Similar Documents

Publication Publication Date Title
US4366361A (en) Method of producing an electrical component
AU598815B2 (en) Circuit breaker contact containing silver and graphite fibers
US2370242A (en) Refractory metal composition
JPS5873707A (ja) ディスクブレ−キ用摩擦要素の製造方法およびその製造装置
US4576872A (en) Friction element and method of manufacture thereof
JP3763006B2 (ja) 銅タングステン合金およびその製造方法
JP4410066B2 (ja) 電気接点材料の製造方法
JP3138965B2 (ja) 炭素をもつ銀で作られた電気接点のための素材
US2706759A (en) Refractory contacts
US3255522A (en) Abrasion resistant material bonding process using boron alloys
JPS61243103A (ja) 不良導体硬質材料粉末と金属粉末より成る複合材の工具チツプの製法
JP2762225B2 (ja) 放電プラズマ焼結方法および装置
DE60025117D1 (de) Legierung für elektrische Kontakte und Elektroden und Verfahren seiner Herstellung
US2652624A (en) Method of producing composite metal
US4859825A (en) Spot welding electrode and method for making it
US4101453A (en) Sintered composition
US2294405A (en) Aluminum base metal composition
US3943625A (en) Method for making tined electrical contacts
US2221286A (en) Electric contact
JP4355431B2 (ja) ピストンの製造方法
US4131460A (en) Method of producing a sintered composition
JP2004300485A (ja) 摺動部品とその製造方法
JPS5823442B2 (ja) 接点ブリツジの製造方法
JP2542038B2 (ja) 電 極
RU2101135C1 (ru) Устройство для горячего прессования электропроводящих порошков

Legal Events

Date Code Title Description
AS Assignment

Owner name: LUCAS INDUSTRIES LIMITED,GREAT KING ST BIRMINGHAM

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:ALLEN, BRIAN R.;REEL/FRAME:004045/0809

Effective date: 19770317

Owner name: LUCAS INDUSTRIES LIMITED, A BRITISH COMPANY, ENGLA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ALLEN, BRIAN R.;REEL/FRAME:004045/0809

Effective date: 19770317

FEPP Fee payment procedure

Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

LAPS Lapse for failure to pay maintenance fees
STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362

FP Lapsed due to failure to pay maintenance fee

Effective date: 19861228